Hand-written denominations.

Initially, company clerks hand-wrote buyers’ names and numbers of shares on every certificate their company sold. Denominations ranged from partial shares to millions of shares. In large companies, that hand work was expensive. Eventually companies reasoned that pre-printed denominations would save time and wages.

The earliest surviving stock certificates with pre-printed denominations date from about 1870. That year, both the Milwaukee & St. Paul Railroad and the International & Great Northern Railroad issued certificates pre-printed with 100-share denominations. A few companies followed suit through the 1870s, but 100-share certificates really caught on in the 1880s.

Certificates specifically marked as 'less than one hundred shares' also appeared as early as 1870. Like 100-share certificates, 'less than 100 shares' certificates were in widespread use by the mid-1880s.

Generally, "less than one hundred share" certificates included "counters" somewhere on the certificate. Counters were normally located within the right margin. They were meant to be punched to correspond to the number of shares purchased. Occasionally, counters were placed along the bottom margin. In some cases, counters included more than two columns of numbers, enabling the companies to issue as many a 9,999 shares. 

The illustration at right shows a counter puched for eight shares.

Currently, the earliest 10-share stock certificate seems to have appeared about 1873, Jay Gould’s heavy selling and stock manipulation forced the introduction of huge quantities of pre-printed 10-share certificates for the Missouri Kansas & Texas line in 1880. About five years later, companies started experimenting with 500-share certificates, but they found little need for such large-denomination certificates.

Other 'oddball' denominations have appeared through time, but except for 50-share certificates, none ever caught on. One-share certificates were used as early as 1845 in the U.S. and were somewhat popular in Mexico and Cuba. At the other end of the spectrum, a handful of 1,000-, 5,000-, and 10,000-share certificates are also known. The highest denominations in the database are currently the <1,000,000-share certificates used by the Union Pacific Corp. into the 1970s.